well in one hand, i felt TF had more development to the story and the autobots while the 2nd one felt more like a decepticon film, its a tough one, it was great to see Sscream and Megs do their stuff reminded me of G1 cartoon,the forest fight was better than some fights in the 1st movie,but the battle in the city was great, Starscream transforming and shooting those helis, when i saw Megs go at it with Prime for the first time i had a geekgasm,and about the humor i think the first one had better stuff ("No those are 3 claws that Wolverine!! HAHA THATS WOLVERINE")
So i´ll have to say TRANSFORMERS, cause nothing, not even a reboot, will never beat the cheer awesomness of seeing a Transformer in the big screen for the first time.